"The fighting started when a splinter sect of Covenant ignored the Ceasefire of 2552 and attacked UNSC forces. By the time the fighting was done... Well, it didn't end well for the UNSC and Covenant, either one."

A Covenant fleet unexpectedly appeared in orbit over Draetheus V and deployed numerous Type-25 Spirit dropships bound for its moon, X50. SpartanEdward Davis was deployed to support the security force of a research project in a location designated CF-32 in the northern continent of X50. After thwarting the initial assault, Davis moved to secure the UNSC's Research Facility Alpha and the Forerunner artifact located therein, which appeared to be this Covenant's main target.[4]

However, the Covenant resumed their assault and the UNSC feared Research Facility Alpha would soon be crushed. Spartan Sarah Palmer, with a Marine detachment, infiltrated artillery positions the Covenant had set up and destroyed them.[5] Spartan Davis later noticed the Covenant's heavy reliance on dropship insertion. Davis realized they would be vulnerable to focused anti-aircraft fire, so, using M9 Wolverines, he began establishing air defenses west of the facility at a location designated Glacial Perch.[6]

While Spartan Davis was successful in slowing the enemy advance, the Covenant forces were too overwhelming. Sarah Palmer began fighting her way upstream through the invasion in an attempt to reach one of the northern outposts. Her plan was to destroy Covenant air support and give the AV-14 Hornets a chance to land near the outposts. The ultimate goal was to get off X50 and warn Draetheus V of the Covenant invasion. Within an hour of their arrival at X50, the Covenant owned the moon. Despite the ferocity of the assault on X50, the UNSC forces on Draetheus V had no idea anything was going on because the planet's unique magnetic resonance frequently made off-world communication nearly impossible.[7]

Spartan Davis fought to hold the line on X50, while Sarah Palmer executed a plan to depart for Draetheus V and warn them of the incoming Covenant invasion of the colony. Palmer ordered the Marines in the area to fall back to the Hornet landing zones. Only six Marines made it there alive. They held out against an overwhelming Covenant force until Palmer managed to escape.[9] Spartan Palmer was successful in warning Draetheus V of the coming attack, which soon hit the colonies' defenses like a tidal wave. Draetheus V's main outpost, Faraday Base, was located on the border of an expanse of dense vegetation to the north and an enormous rock plateau to the south.

Spartan Palmer defending Faraday Base.

When the Covenant invasion force eventually arrived, the first defense lines surrounding Faraday were quickly breached before the base's sentry turrets were fully operational. Palmer took to the field and almost singlehandedly held off the waves of Unggoysuicide units crashing down on the thick concrete wall behind the defense lines.[10]

Draetheus V's western reactor field was one of the largest of the magnetic reactor stations and was of great interest to the Covenant. Luckily, the trench-like layout of the reactor field provided the Marines stationed there with a terrain advantage and Covenant infantry platoons had significant difficulty in seizing the station. After supporting the Marines at Faraday, Sarah Palmer moved to provide support in the western reactor field. Palmer's prime objectives were to protect several squads of M9 Wolverines and halt the Banshees providing air support to the Covenant infantry.[11]

After Faraday Base's defense were stabilized Spartan Palmer began trying to establish the location of the Covenant officers leading the invasion. After taking significant losses, Marines of the 21st Scout platoon had managed to uncover a set of promising coordinates. These commanders' locations were well hidden by Draetheus V's unique magnetic signatures. Without Palmer, the officers might have remained hidden for days. She found them within 30 minutes and eliminated them quickly.[12]

Nine lofty bridges spanning an enormous gorge called the Epsilon Expanse allowed for access to the southern plateau where the majority of Covenant landing zones were located. The Covenant quickly secured these bridges and held UNSC forces at bay with heavy artillery. Spartan Palmer escorted the 23rd Armored Cavalry to the Epsilon Expanse, but the Scorpion tanks would not survive the guaranteed heavy artillery fire. Taking a small team of Marines across one of the bridges, Palmer managed to infiltrate the Covenant camps and destroy several artillery turrets, giving the Scorpions the chance to advance and launch a counter-offensive.[13]

A Scorpion engages a Wraith at the Red Slate Plateau.

With the Covenant's southern forces exposed, Spartan Palmer and the 23rd Armored Cavalry's massive column of M808 Scorpions and M850 Grizzlies rushed across the Red Slate plateau on a collision course with several Covenant tank battalions. Only a UNSC counter-offensive would prevent Faraday from being crushed between the northern and southern front. The 23rd had brought eighty-six vehicles to Draetheus V. After the battle at Red Slate, there were only eight functioning vehicles left.[14]

"Even through the battle was going in the Spartan's favor, Draetheus V had a surprise in store. Its moon wasn't a moon at all. It was a Forerunner creation, designed to build and destroy entire planets. Nobody knew about this... until the Covenant cult leader found a way to reactivate the old Forerunner tech... and start disassembling Draetheus V."

As Spartan Palmer led the charge on Draetheus V, Spartan Davis continued to face considerable enemy threat on the moon. Furthermore, it was revealed that X50 was not a natural moon after all, but a Forerunner megastructure capable of constructing and destroying planets. Upon finding his way into the control center, Merg Vol tuned X50's main weapon on Draetheus V and began to dismantle the planet.

In a stroke of luck, the UNSC Eminent Domain was able to outmaneuver Covenant forces in orbit over the moon and offer some support by deploying marines to the southern Mirror Flats. The 3rd Helljumper Platoon was the first to land on Draetheus V's moon. Their drop zone was less than a mile from Alpha facility but the landing scattered them across the razor sharp rock face of the mountain range called Glacial Perch. They were quickly surrounded by Covenant infantry and taking heavy losses. Spartan Davis, having held out against a constant stream of Unggoy and Sangheili for a full day, quickly set out to clear the landing zone for the second wave of drop pods.[16]

Having secured a safe landing zone at the Glacial Perch, Davis moved to regroup with a second platoon of marines, whose pods were coming down among dozens of crashed Spirits. These Spirits were destroyed from orbit by UNSC Eminent Domain just as the ship itself was destroyed. Davis and the Marines found Covenant infantry swarming from the wrecked Spirits, angry and looking for payback. They engaged and neutralized the enemy forces in the area.[17]

South of the Forerunner structure, a collection of thousands of spiked rock formations known as the Basalt Maze protruded from the moon's thick ice. Covenant supply lines were running straight through the Maze to set up more defenses around the Forerunner structure. Spartan Davis connected with UNSC combat technicians who believed they could render the Forerunner structure inert; they just needed the chance to get inside the structure. Getting the combat engineers close to the Forerunner structure would be extremely difficult, so Davis created a diversion to provide them with the best chance. The Basalt Maze provided an ideal location for his plan.[18]

Covenant forces established a mile wide defense perimeter around the Forerunner structure. To protect the technicians, UNSC command had deployed snipers among the Marine reinforcements. They would provide suppressing fire from the higher ground around the structure. However, the area they were deploying to was swarming with Stealth Sangheili. Spartan Davis escorted several sniper teams to their locations and cleared the area of any distractors in the process. Without his support, the sniper squads would not have had a chance to make it safely to their assignments.[19]

Spartan Davis and the remaining Marines assisted the combat technicians securing the Forerunner structure while the Covenant reinforcements did everything in their power to stop the technicians. With supporting sniper fire from higher grounds, Davis and his men were able to buy the technicians just enough time to do their work. However, even with their job complete, it was too late for Draetheus V. In the sky they could see the planet had already begun to violently break apart.[20]

Across Draetheus V, the effects of the activation of the moon's Forerunner structure were being felt. Enormous slabs of rock were slowly floating away from the planet's surface and both UNSC and Covenant troops were scrambling to get to safety. Spartan Palmer needed to get every last survivor off Dratheus-V as soon as possible. But as the planet started to disintegrate, a panic rippled through every infantry unit on the field. A coordinated retreat would be impossible. Fighting her way through hordes of fleeing Covenant in a rapidly disintegrating base, she managed to secure jetpacks to get her to safer ground.[22]

Despite the chaos, much of the Covenant force remained rooted in strategic locations within the area around Faraday Base. The few surviving Marines and base staff had set up defensive positions in the western sector of the facility, preparing for a last stand against the increasing influx of Covenant. Palmer arrived at the base's perimeter moments before the Marines would be overrun. Around the base, Palmer managed to secure several M312 Elephants. She then needed to relieve the besieged Marines and get them out of their predicament. She was able to rescue several groups of Marines and escort them to the extraction zone.[23]

Grizzly tanks during the assault on the Covenant landing zones.

Draetheus V was ill-prepared for a full evacuation. Many ships had been destroyed in the initial Covenant assault. UNSC command estimated that at best, 40 percent might reach safety while the rest would die. Spartan Palmer declared those odds unacceptable and hatched a plan to abuse the rapidly degrading Covenant morale to overrun their landing zones and confiscate their spacecraft. The Covenant forces stationed at the landing zones were completely surprised by the bold attack. Already displaying cracks in their morale due to earlier losses, the Covenant forces quickly gave up the landing zones.[24]

Strategic location at the Epsilon Expanse had been hard won, and a rear guard was established at each of the bridge's exit points to cover the convoy of Elephants taking the evacuees south. Spartan Palmer knew that taking a slow-moving pack of transport vehicles across a quickly degenerating warzone was not going to be easy. While earlier operations at the Epsilon Expanse had secured access to the Red Slate Plateau, hordes of Covenant were overrunning the area, also trying to get to their ships in the south. These forces quickly diverted their attention to the fleeing Elephants. Palmer with the help of several Marines was able to defend the Elephants.[25]

Spartan Davis makes his last stand against Covenant forces.

After getting her convoy of Elephants safely across the Plateau, Spartan Palmer organized the construction of a series of makeshift defensive structures in order to protect the ships as evacuees loaded. With a mix of outrage and desperation, the Covenant fought to reclaim their only means of escape. After succeeding in holding off the Covenant infantry, Palmer managed to get 23 Covenant spaceships off the ground, saving hundreds of lives that would have otherwise been lost.[26] Meanwhile, on X50, Davis' position was overrun by the Covenant and he was eventually killed.[27]

With transportation secured, one last hurdle remained in getting the colonists safely off of Draetheus V. The leader of the Covenant forces, Merg Vol, was still present on moon X50, providing the remaining Covenant forces with a rallying point and cry. If the colonists were to leave Draetheus V's orbit alive, Merg Vol would need to be terminated. Spartan Palmer would need a way to get to the moon unseen, but the Covenant knew about her stolen Spirits and would likely open fire on any of these ships trying to land on the moon. Palmer suspected the Covenant's officer on Draetheus V, Parg Vol had a personal transport hidden away. After completing the evacuation operation, locating Parg Vol's ship became Palmer's highest priority. After fighting through heavy Covenant forces she was able to locate Vol's Phantom and secured it for hijacking.[28]

Parg Vol's camp was easily defensible, but Spartan Palmer neutralized the perimeter guard and moved in. The real challenge would be in accessing Parg Vol's Phantom. While a combat technician was by passing the Phantom's security protocols, Parg Vol made his return. When he realized Palmer's intent, he ordered a full frontal assault on her position. With heavy plasma artillery raining down from a platoon of Wraiths, Palmer held off the infantry just long enough for the technicians to succeed.[29]

Merg Vol's base on the moon was surrounded by Type-38 Tyrants. Hearing of Spartan Palmer's theft of Parg Vol's ship, Merg Vol ordered every flying craft to be shot down, the only exception being commanding officers' Phantoms. Having successfully piloted the Phantom through the Covenant fleet orbiting Draetheus V's moon, Palmer was able to land south of Merg Vol's camp, out of range of his turrets. Her Trojan Horse tactic had worked. Although she was closing in on Merg Vol, she still had to fight her way through a heavily fortified camp of his most seasoned soldiers. To ease her work, she entertained possibility of a plan to persuade them to leave the safety of their positions.[30]

Sarah Palmer facing down Merg Vol.

In the hours since launching their attack, the Covenant cultists had established themselves in a long ice-covered gorge between Merg Vol's camp and the Forerunner structure, setting up an almost-impregnable position. With Merg Vol's camp neutralized, Spartan Palmer made her way to the Forerunner structure. The Covenant troops there were Merg Vol's most devout followers and threw themselves at her mercilessly. Palmer would have to battle her way through heavy opposition, and before she could confront Merg Vol himself, she first needed to deal with his lieutenants. After facing heavy resistance, Palmer was able to eliminate Merg Vol's lieutenants.[31]

Merg Vol was convinced he had been chosen by his gods to wield the power contained within the Forerunner structure. Having spent considerable resources to unlock its secrets, Vol managed to activate the structure's emergency defenses. With the deadly defenses at his command, Vol had become extremely dangerous. Unable to contact Spartan Davis since landing on Draetheus V's moon, Palmer prepared to battle Vol on her own. Vol's exact location had not been difficult to find: the direct area at the foot of the Forerunner structure was littered with a trail of dead UNSC soldiers. After facing Merg Vol's final forces and Forerunner beam turrets, she engaged Merg Vol himself. Despite a difficult fight, Palmer was able to overtake Vol and executed him with her M6H magnum.

With Merg Vol killed and the Covenant forces were defeated and the surviving colonists of Draetheus V were able to safely evacuate the system. After killing Vol, Palmer sabotaged the Forerunner device on X50.[32]

With the Covenant defeated and most UNSC forces evacuated from Draetheus V and X50, the battle appeared to be over. However, the UNSC soon detected a looping transmission of low-frequency static, identified by UNSC analysts as a string of Forerunner code, emanating from X50. Spartan Palmer returned to X50 to discern the origin of this signal, only to discover that the Covenant had also returned.[34] The Covenant believed that one of their gods was speaking to them and were intent on preventing the humans from intercepting the message. Once Spartan Palmer secured a landing zone, UNSC forces were re-deployed to X50's surface in a constant stream, as part of Operation: HYDRA.[35][36]

While UNSC scientists struggled to pinpoint the Forerunner signal's origin, Covenant forces recaptured a series of turrets along a large gorge called the Arid Sea. The UNSC forces would require significant fire power to break through. Spartan Palmer took command of a battalion of Scorpions and Grizzlies in an effort to take down the Covenant turrets. Meanwhile, UNSC scientists began to crack the Forerunner code. They were beginning to suspect that instead of an ancient voice, it was something much more recent in origin, and was calling for help.[35]

The disintegration of Draetheus V caused large chunks of the planet's crust to crash into X50's surface. The impact of the collisions revealed sections of a Forerunner structure that were previously hidden under the moon's ice. The structure was enormous in scale, stretching for miles in all directions. It was deduced that this structure was the origin of the Forerunner message. With the main line of the Covenant defenses breached, Spartan Palmer moved to locate the source of the Forerunner transmission. The terrain of X50 was too challenging for the battalion to pass, so Palmer continued on foot towards the Forerunner signal.[37]

"The transmission was Davis's call for help, just before he died. That planet was made to build things out of galactic material. And it tried to build something out of was left of Davis. I shut it down."

After defeating the Covenant forces at the light bridge at the entrance to a series of caverns, Spartan Palmer entered a cave UNSC Command designated the Cistern. Palmer advanced forward, encountering and dispatching the large numbers of stealth Sangheili forces in the area. Deep within the Cistern she found the structure's entrance; large blast doors of Forerunner design, and from behind the doors, the origin of the signal. At this time, UNSC scientists decoded the first part of the Forerunner transmission, which was a single word: "Palmer." They warned the Spartan that the structure seemed to know her name.[38]

Engineering equipment became increasingly unreliable while moving further into the Cistern. The Forerunner signal interfered with anything capable of picking it up. Engineering worked franticly to keep their equipment in running order, though Spartan Palmer's MJOLNIR armor was able to withstand the interference. Palmer followed the signal deeper into the caves, eventually to its very source. As she got closer, the Forerunner code rippled across her sensors, translating before her very eyes as "Palmer, help me."[39] Palmer discovered that the message had originated from her Spartan compatriot Davis, moments before his death. The structure had absorbed Davis' remains into a mysterious device. Palmer shut the device down in order to allow her friend to pass away peacefully.[33] A Pelican subsequently recovered both Palmer and the now-inert container housing Davis' remains.[39]

With the Forerunner device sabotaged and Merg Vol dead, the Covenant were unable to achieve their goal. While numerous human lives were lost over the course of the battle, many more deaths were avoided thanks to the efforts of the Spartans.

Years later, the records of the Battle of Draetheus V became part of a tactical simulator to enhance strategic skills of the SPARTAN-IVs.[40] However, the events after Palmer killing Merg Vol and sabotaging X50 were not included in the official record. Despite this, Palmer revealed the truth to a small number of Spartans aboard UNSC Infinity.[33]